1. Selection of Capacity Selection of capacity depends on: Physical characteristics Physical characteristics Inflow outflow characteristics Inflow outflow characteristics

2. Reservoir Storage Zones Dead Zone is reserved for sediments deposits. Dead Zone is reserved for sediments deposits. Live zone is active zone where outflow calculation is based on. Live zone is active zone where outflow calculation is based on. Flood protection zone is reserved to protect the dam from successive high floods. Flood protection zone is reserved to protect the dam from successive high floods. Dead Storage Zone Live Storage Zone Flood Protection Zone

3. Spillway Dam Spillway

5. Annual Storage Annual storage is selected when: 1. Inflow exceeds the requirements but basin topography does not permit long term storage. 2. Inflow equals requirements but they do not match in timing.

7. Mass Curve Method The mass curve is used to determine the capacity of the reservoir. A plot of the accumulated inflow and outflow is prepared. The maximum difference between the two curves represents the required capacity.

9. Example: Example: Find the required storage for the following stream? Storage m 3 /month Losses m 3 /month Outflow (demand) m 3 /month Inflow (supply) M 3 /month Month 3717451 7318452 7818143 7918104 762985 6731156 5531127 4421128 3321129 22211210 111 1 01 112 20117137